Hydraulic system comprising multiple pump and ram units



O 1956 J. s. PILCH v 2,768,499

HYDRAULIC SYSTEM COMPRISING MULTIPLE PUMP AND RAM UNITS Filed April 20,1955 5 Sheets-Sheet 1 INVENTOR. JOHN $.PILCH J. S. PILCH Oct. 30, 1956HYDRAULIC SYSTEM COMPRISING MULTIPLE PUMP AND RAM UNITS 5 Sheets-Sheet 2Filed April 20, 1953 ATTORNEY Oct. 30, 1956 J. s. PlLCH ,7

HYDRAULIC SYSTEM COMPRISING MULTIPLE PUMP AND RAM UNITS Filed April 20,1953 5 Sheets-Sheet 3 INVENTOR. JvOH N S. PILCH Oct. 30, 1956 J. s.PILCH 2,763,499

HYDRAULIC SYSTEM COMPRISING MULTIPLE PUMP AND RAM UNITS Filed April 20,1955 5 Sheets-Sheet 4 INVENTOR.

in i Oct. 30, 1956 J. s. PILCH 2,768,499

HYDRAULIC SYSTEM COMPRISING MULTIPLE PUMP AND RAM UNITS Filed April 20,1953 I 5 Sheets-Sheet 5 INVENTOR. JOHN 6. Pl LCH ATTOENEX United StatesPatent HYDRAULIC SYSTEM COMPRISING MULTIPLE PUMP AND RAM UNITS John S.Pilch, Ware, Mass.

Application April 20, 1953, Serial No. 349,716

2 Claims. (Cl. GAL-B) This invention relates to a backhoe or the likeand has particular reference to an all hydraulic apparatus adapted foruse with a tractor which is adapted to supply power for the apparatus.

Another object is to provide a device of the type set forth which isrelatively compact and which allows a side range of operation withoutdanger or damage to the apparatus caused by stones or otherobstructions.

Another object is to provide a new and improved device of the type setforth which is capable of performing work not previously possible withbackhoes and which has greater mobility and can move easily from job tojob under its own power and i ready to dig upon arrival.

Another object of the invention is to provide a relatively simple andeconomical device which is capable of operation comparable to much morecomplicated and expensive devices.

Another object is to provide a unit of the type set forth which may bemounted on a conventional tractor without requiring a completely specialunit.

Another object is to provide a new and improved dual hydraulic systemfor apparatus of the type set forth which allows use of two hydraulicsystems separately or simultaneously or the cumulative hydraulic forcesof the two systems employed as desired.

Another object is to provide a new and improved hydraulic arrangementfor apparatus of the type set forth which provides much greater speedand power of operation.

Another object is to provide a new and improved bucket and dipper stickarrangement for devices of the type set forth which arrangement is soformed that the dipper stick connection with the bucket is inwardly fromthe edge of the bucket for clearance and also to prevent interferencewith outside objects during the operation of the device.

Other objects and advantages of the invention will be apparent from thefollowing description taken in connection with the accompanyingdrawings. It will be understood that changes may be made in the detailsof construction and arrangement of parts shown and described, as thepreferred form has been given by way of illustration only.

Referring to the drawings:

Fig. l is a side view of an apparatus embodying the invention;

Fig. 2 is a side view taken from the side opposite that shown .in Fig.1;

Fig. 3 is a top or plan view of the apparatus;

Fig. 4 is a diagrammatic view illustrating the hydraulic system of theinvention;

Fig. 5 is a fragmentary sectional view taken on line 5-5 of Fig. 3,looking in the direction of the arrows; and

Fig. 6 is a fragmentary front view showing the new bucket and dipperstick arrangement.

Referring more particularly to the drawings wherein similar referencecharacters designate corresponding parts "ice throughout the severalviews, the apparatus shown embodying the invention .is shown mounted ona tractor comprising a frame 10 supporting the engine 11 and providedwith the seat 12 and steering wheel 13 for the operator.

Behind the seat 12, that is, on the side thereof opposite the engine 11is positioned the stationary upright cylinder 14 surrounding which ispositioned the spool or pivotable cylinder 15 and between the twocylinders 14 and 15 is positioned the bearing sleeve 16 which forms abearing for pivotable cylinder 15.

Adjacent its lower end, the pivotable cylinder 15 is connected to thedrive ring 17 which is mounted for rotation on bearing ring 18 on frame10. Drive ring 17 has the toothed periphery 19 engaging chain drive 29which has its ends connected to rams 21 and 22 which eX- tend int-ocylinders 23 and 24 respectively, whereupon movement of rams 21 and 22in opposite directions in their respective cylinders will effectcorresponding movement of chain 20 and thereby eifect rotation of turret15 on which is pivotally mounted the boom 25 adjacent the :lower end ofturret 15 and the boom operating cylinder 26 on support 27 which isconnected to turret l5 and extends -thereabove. The boom 25 is pivotallyconnected at 28 and cylinder 26 is pivotally connected at 29.

Dipper stick Si) is pivotally connected to the boom 25 adjacent the freeend. of the boom 25 at 31. Cylinders 32 are pivotally connected to boom25 at 33 and rams 34 which extend into cylinders 32 may be pivotallyconnected to either of the pivotal connections 35 or 36 on dipper stick30 depending upon the work for which the 'apparatus is to be employed.

Adjacent the lower end of dipper stick 3% is pivotally connected thebucket 37 at 38 and cylinder 39 which is pivotally connected at 40 todipper stick 30 ha ram 41 extending therein. Ram 41 is connected tobucket 37 through linkage comprising links 42a and 42 and cylinder 39and ram 41 are adapted to effect rotation of bucket 37 relative todipper stick 30 for loading and unloading the bucket. Link 42a ispivotally connected to dipper stick 30 as shown.

It will be seen from Fig. 6 that the lower end of dipper stick 30 isnarrower than bucket 37 and is spaced inwardly of the edges of thebucket thus providing clearance and preventing interference during theoperation of the apparatus.

The pusher and stabilizer 43 is mounted on supports 44 which arepivotally mounted at 45 to tractor frame It) and pusher 43 and supports44 are adapted to be raised and lowered by means of cylinders 46 whichare pivotally connected at 47 to lug 48 on frame lit and have rams 49extending therein which are pivotally connected at 50 to supports 44whereupon movement of ram 49 in cylinder 46 effects raising and loweringof supports 44 and pusher 43.

As will be seen from Fig. 4, the hydraulic system includes the hydraulicpump 51 which is adapted to be driven by the tractor engine whichreceives fluid from hydraulic tank 52 and supplies fluid through valvebanks 53 and 54 to the various operating cylinders.

Valves 53 and 54 are adapted to be controlled by operating levers 55 and56 respectively.

As will be seen from Fig. 4, hydraulic pump 51 is a dual pump adapted tosupply fluid under pressure to valves 53 and 54 simultaneously throughlines 57 and 58 respectively and each of the principal valves of controlvalves 53 and 54 is connected to each of the operating cylinders eitherby separate lines or by lines which are joined intermediate their endsas shown.

It will thus be seen that the boom control or lift cylinder 26 isconnected through lines 58 and 59 to valve banks 53 and 54 respectively,and also it will be seen that certain of the cylinders are connected tocontrol valves 53 and others to control valve 54, for example, bucketcontrol cylinder 39 is connected to valve 54 through lines 61 and 62,dipper stick control cylinders 32 are connected to valve 54 throughlines 63 and 64 and the stabilizing or pusher cylinders 46 are connectedthrough separate sets of lines 65 and 66 and 65a and 66a to valve 53.Also the swing cylinders 21 and 22 are connected through lines 67 and 68which are connected through relief valve 69 to valve 53. Relief valve 69is provided for cushioning the action of cylinders 21 and 22. Theopposite ends of cylinders 23 and 24 are connected through the commonline 70 to the tank 52.

It will be seen from the above that in view of the fact that certain ofthe cylinders are controlled through operating valve 53 and other of thecylinders are controlled through valve 54 and also that other of thecylinders such as the boom lift cylinder are connected to both thevalves 53 and 54 that it is connected to both of the valves such as theboom lift may be subjected to the accumulative force of both hydraulicsystems. For example, if the flow of the hydraulic system through valve53 is twenty gallons per minute and that through valve 54 is fifteengallons per minute, it is possible to subject the boom lift cylinder toeither a fifteen or a twenty gallon per minute flow or the total of thetwo systems making a total of thirty-five gallons per minute. Thisarrangement may be employed in connection with any desired cylinders orall cylinders as desired.

Also because of the separate hydraulic systems and control valves, it ispossible to operate the boom and simultaneously operate the swingcylinders for changing the angular position of the boom, thus makingpossible the use of the two systems simultaneously. It will be seen thatbecause of the dual hydraulic systems, the boom and dipper stick systemsmay be operated simultaneously or the swing and dipper stick systems ofthe swing and bucket control systems simultaneously, whereas in the pastif one section of the hydraulic system was used for one purpose it wasnot possible to simultaneously use another portion of the hydraulicsystem for another purpose.

From the foregoing it will be seen that I have provided simple,economical and efiicient means for obtaining all of the objects andadvantages of the invention,

I claim:

1. A hydraulic system for a trencher, or the like, comprising multiplehydraulic cylinder and ram means, a tank for hydraulic fluid, a firstpump taking suction from said tank and supplying hydraulic fluid underpressure to a first valve bank, a return line from said first valve bankto said tank, said first valve bank comprising a plurality of valveseach valve having two connections, one to each end of a differentoperating cylinder of a first set of cylinder and ram means, a secondpump taking suction from said tank and supplying hydraulic fluid underpressure to a second valve bank, a return line from said second valvebank to said tank, said second valve bank comprising a plurality ofvalves, each valve having two connections, one to each end of adifferent operating cylinder of a second set of cylinder and ram means,at least one of said multiple hydraulic cylinders being provided withconnections from one valve of each said first and said second valvebanks.

2. The hydraulic system of claim 1 in which said first and second pumpsare of different capacities whereby the hydraulic cylinder which isconnected to both valve banks may be operated under the influence of oneor the other of said pumps of different capacities or of both of saidpumps to give a selection of operating characteristics to that cylinder.

References Cited in the file of this patent UNITED STATES PATENTS D.162,873 Pilch Apr. 10, 1951 1,890,727 Fundom Dec. 13, 1932 1,926,692Tarbox Sept. 12, 1933 2,103,530 Henry Dec. 28, 1937 2,301,122 Kellett,Jr. Nov. 3, 1942 2,331,790 Nichols Oct. 12, 1943 2,501,387 Haumann Mar.21, 1950

